This document summarizes key aspects of venous circulation of the heart, the coronary sinus, fetal circulation, and nerve supply of the heart. It notes that around 60% of venous blood from the heart drains into the right atrium via the coronary sinus, while the rest drains into heart chambers via other veins. It describes the anatomy and tributaries of the coronary sinus. It then briefly outlines fetal circulation via the umbilical cord, ductus venosus, foramen ovale and ductus arteriosus. Finally, it summarizes the parasympathetic and sympathetic nerve supply to the heart via the cardiac plexuses.

1. BY:-
APAAR KAUSHIK
ANOOP SINGH RATHORE

2.  VENAL CIRCULATION OF HEART
 INTRODUCTION
 CORONARY SINUS
 FOETAL CIRCULATION
 NERVE SUPPLY OF HEART

3.  About 60% of venous blood drains into right
atrium via coronary sinus, while rest 40% drains
into different chambers via anterior cardiac
veins & venae cordis minimi.
 Coronary sinus conveys greater part of blood fro
left coronary artery.
 Anterior cardiac veins drains blood of right
coronary artery.
 Veins which donot join coronary sinus are:-
1.Anterior cadiac veins
2.Venae cordis minimi

4.  Wide venous channel
 2-3 cm long
 Situated in posteriorpart of atrioventricular groove.
 COURSE:-
 TRIBUTARIES:-
1. GREAT CARDIAC VEIN
2. MIDDLE CARDIAC VEIN
3. SMALL CARDIAC VEIN
4. POSTERIOR VEIN OF LEFT VENTRICLE
5. OBLIQUE VEIN OF LEFT ATRIUM

5.  Foetus depends on its mother for entire nutrition through placenta.
 Umbilical cord contains:-
1. 2 umbilical arteries(returns nonoxygenated blood, fecal waste & carbon dioxide to
placenta)
2. 1 umbilical vein(brings oxygenated blood & nutrients to foetus)
1. Course of oxygenated blood:-
placenta
Body of foetusLeft ventricleLeft atrium
Foramen ovale
Inferior vena cava
Ductus venosus
Umbilical vein

6.  COURSE OF DEOXYGENATED BLOOD:-
Blood
Superior vena cava
Right atrium
Right ventricle
Pulmonary trunk
Right lung
&
left lung
Ductus arteriosus
Descending aorta
Abdominal aorta
Common iliac artery
Umbilical arteries Placenta
Mother

7. •Both parasympathetic and sympathetic nerves form superficial & deep
cardiac plexuses.
 It reaches heart via vagus nerve
 These are cardioinhibitory, on
stimulation they slow down the
heart rate.
 These are derived from the upper
T1-T5
 These are cardioacceleratory, on
stimulation they increase the
heart rate & also dilate the
coronary arteries.
SUPERFICIAL CARDIAC PLEXUS DEEP CARDIAC PLEXUS
1. It is situated below arch of aorta in front of
right pulmonary artery. It is formed by:
i. Superficial cervical cardiac branch of
left sympathetic chain
ii. Inferior cervical cardiac branch of left
vagus nerve.
1. It is situated in front of bifurcation of trachea,
& behind arch of aorta.
2. It is formed by
i. cardiac branches derived from all
cervical & upper thoracic ganglia of
sypathetic chain
ii. cardiac branches of vagus & recurrent
laryngeal nerves, except those which
form the superficial plexus.
PARASYMPATHETIC NERVES SYMPATHETIC NERVES